1. Field of the Invention
The present invention relates to a signal reproducing apparatus and, particularly, to a signal reproducing apparatus suitable to reproduce a plurality of signals of various kinds simultaneously from a recording medium on which the plurality of the signals obtained by dividing a video signal are recorded.
2. Related to the Prior Art
FIG. 1 shows a conventional tape pattern and FIG. 2 is a block diagram showing a conventional video signal reproducing apparatus. Conventional techniques will be described with reference to these figures.
In a conventional video signal reproducing apparatus (referred to as "VTR", hereinafter), one track is formed per one video field as shown in FIG. 1 by using a pair of magnetic heads H1 and H2 arranged on a rotary drum with a space of 180 degrees therebetween.
An auto-tracking has been known, in which, in reproducing signals on a magnetic tape T, a tracking is performed on the basis of an amplitude level of a reproduced signal. A VTR which performs such tracking will be described with reference to FIG. 2. In FIG. 2. signals reproduced from the magnetic tape T by means of the magnetic heads H1 and H2 are supplied to a selecting circuit 3 through preamplifiers 1 and 2. Since the recorded signal is reproduced by the magnetic heads H1 and H2 arranged on the rotary drum with a space of 180 therebetween, when one of the preamplifiers 1 and 2 outputs a signal, the other preamplifier does not. The selecting circuit 3 selects these output signals of the preamplifiers by using drum pulse which is synchronous with rotation of the rotary drum to form a continuous signal which is supplied to a reproduced signal processing circuit 4 and a rectifier circuit 5. The reproduced signal processing circuit 4 sends a reproduced video signal 4a obtained by demodulating an FM modulated video signal to a transmission line which is not shown.
On the other hand, the output signal of the selecting circuit 3, which is supplied to the rectifier circuit 5, is half-wave or full-wave rectified thereby and then filtered by an integration circuit 6 to remove its high frequency component, resulting in an amplitude level detection signal 6a corresponding to an amplitude level of the reproduced signal. The amplitude level detection signal 6a is supplied to an operation circuit 7 composed of such as CPU to produce a control signal 7a such that the amplitude level detection signal 6a becomes maximum and the control signal 7a is supplied to a capstan servo control system which is not shown and which controls a running speed of the magnetic tape T such that a positional relationship between the magnetic heads H1 and H2 and the magnetic tape T becomes optimal.
In the conventional technique, the tracking servo control is performed such that amplitude level of a reproduced signal of one channel becomes optimal, as mentioned above.
On the other hand, the applicant of this application has proposed a VTR for dividing and recording a high definition video signal (Japanese Patent Application H5-73067). A tape pattern obtainable by such VTR is shown in FIG. 3 includes three tracks per field. That is, magnetic heads A1, WP2 and WQ1 shown in FIG. 3 record or reproduce simultaneously as a first channel and magnetic heads A2. WP1 and WQ2 record or reproduce simultaneously as a second channel. The magnetic heads A1 and A2 among them are used for audio signal and the magnetic heads WP2 and WQ1 and the magnetic heads WP1 and WQ2 are used for video signal.
In case where such tape pattern is reproduced, there are reproduced signals of two kinds related to the magnetic heads WP1 and WP2 and the magnetic heads WQ1 and WQ2, respectively. Particularly, in case of separate recording and reproducing in which a recording device and a reproducing device are independent from each other and the recording and reproducing operations are performed without using common heads and common tape running device, one of the two reproduced signals does not always in highest level while the other reproduced signal is in highest level, due to difference in mounting height between the magnetic heads and/or slight difference in lead angle of the rotary drum for guiding the magnetic tape. Therefore, a concord of the both signals is necessary. However, it is impossible to obtain such concord in the above mentioned tracking system.